Sugar centrifugal charging apparatus



Feb. 18, 1958 J. HERTRlcH 2,823,805

SUGAR CENTRIFUGAL CHARGING APPARATUS Filed Aug. l5, 1952 M l* 4;, /V f fifi- IN1/Emme.'n

wwf/ww United States Patent O SUGAR CENTRIFUGAL CHARGING APPARATUS Joseph Hertrich, Hamilton, Ohio, assignor to The Western States Machine Company, Hamilton, Ohio, a corporalion of Utah Application August 15, 1952, Serial N o. 304,515

Claims. (Cl. 21o-360) This invention relates to new and improved charging apparatus for introducing charge material into cyclically operated centrifugal machines of the type used in the manufacture and refining of sugar.

Heretofore, the loading of sugar centrifugals has involved seemingly necessary expenditures of time and physical burdens on skilled workmen who attend the machines, in connection with the opening and closing of a curb top cover and the scraping out of a charge-guiding drip pan at the time of each loading operation. Ineiciencies also arise in many installations from the freezing of loading gates in :closed position between successive loading operations, and from the tendency of charge material flowing from the loading gate to splatter and solidify on exposed surfaces that should be kept clean and sanitary.

Automatic controls have been provided for governing the operations of loading gates which serve sugar centrifugals, but these controls still leave problems in connection with the operation of the curb top covers, the scraping out of drip pans, the tendency of loading gates to stick in closed position and the splattering of charge material about the machines. To bring about the curb cover movements and the drip pan scraping by automatic Icontrol would necessitate extremely complex and expensive control mechanisms, and these still would not eliminate the other problems above mentioned.

The primary object of this invention is to provide a unitary charging apparatus for sugar icentrifugals which overcomes the several problems above mentioned in an eicient and inexpensive manner, and which can be used in conjunction with automatic centrifugal control mechanisms for the provision of Icyclical sugar centrifugals which are completely automatic yet thoroughly reliable in their operations.

According to this invention the sugar centrifugal is provided with a curb which normally is closed at the top so as to exclude the outside atmosphere from the environs of the basket, and this curb is connected with an enclosure which extends from the top of the curb to and around the loading gate of the charge material tank serving the machine, in fa position to surround the path of charge material flowing from this gate into the basket and to unify the moist, warm atmosphere ambient to the basket with the atmosphere ambient to the loading gate. With this apparatus the successive loading and spinning operations may be performed without any need for opening and closing a movable curb top cover between such operations and without exposing either the basket or the loading gate to the atmosphere of the room in which the machine is located, or losing the Warm, moist air from the basket environs to that atmosphere. Moreover, with this apparatus the loading gate itself is advantageously positioned with its gate opening lying directly over the mouth of the extended enclosure and the top opening of the centrifugal basket, so that charge material flowing from the gate in each loading operation falls directly ,into

Patented Feb. 18, 1958 the basket and requires no use of a charge-guiding drip pan.

By means of an apparatus of this nature, the several problems above mentioned are overcome in an extremely etiicient and inexpensive manner. The curb top extension enclosing the loading spout and the path of the charge material eliminates the need for movements of fa curb top cover, but without sacrificing the value of keeping the centrifugal basket enclosed against the free access of cooling and drying air currents. At the same time, it unifies the atmospheres ambient to the basket and the loading gate, so that the loading gate is maintained in a warm, moist condition and shows little or no tendency to stick or freeze in closed position as it often does when dealing with easily crystallized charge materials. Moreover, the charge-guiding function of the usual drip pan can be eliminated altogether, with elimination of the loss of time and the physical burden involved in the scraping out of such a drip pan at the end of each loading operation. l

In the charging of sugar centrifugals, there is a likelihood of the, charge material splashing and accumulating on exposed surfaces of the machine. However, by using the apparatus here disclosed, no splashing charge material reaches surfaces exposed to the outside atmosphere, and such material as may accumulate on the gate surface or on inner surfaces of the charge enclosure is not exposed to an unsanitary atmosphere and can be readily removed from these surfaces. To dispose of such accumulations and to keep these surfaces clean and san-itary, a spraying device manipulated by the attendant is provided inside the enclosure and movable so as to direct a washing .fluid over the surface of the gate and inner surfaces of the enclosure.

Other objects, features and advantages of the invention will become apparent from the following detailed description and the accompanying drawings showing an illustrative embodiment of the invention.

In the drawings:

Figure 1 is a fragmentary side elevation, partly in section, of a sugar centrifugal installation constructed according to a preferred embodiment of the invention, parts of the apparatus being shown in different positions by full and broken lines;

Figure 2 is a perspective View of the charging apparatus of Figure l. looking toward the apparatus from a point in front of the apparatus.

In the illustrated embodiment sugar massecuite is delivered for centrifugal treatment from a mixer tank 10 through a spout 11 and any suitable loading gate, for example, a gate of the construction disclosed in my U. S. Patent No, 2,337,817. The massecuite flows from the gate into a sugar centrifugal 12 which includes a stationary curb or casing 13 yand a rotatable basket 14 carried by rotary spindle 15 in the usual manner, The basket is perforated at 16 for filtering syrup from the sugar in the massecuite being processed.

Delivery of successive centrifugal charges from the` tank to the basket is controlled by a gate member 17 which is moved over the gate opening 18 (Fig. 2) along a facing 19 on gate body 20. The gate is operated by either manual or automatic movement of a lever 21 about the axis of shaft 22 to which it is fixed. The upward and downward movements of said lever respectively raise and lower a crosshead 23, together with the gate member 17, through a pair of levers 24, 25, only one pair of which is shown in the drawings, on each side of the gate. The crosshead is positioned between upper and lower pairs of flanges 26 and 27, respectively, on the gate member and moves the gate by butting against one pair of these flanges whenever it is raised and against the other pair whenever it is lowered,

The basket 14 of the centrifugal has a top opening 28 for admitting charge material to the basket. In order to'exclude the outside atmosphere from the environs of the basket, the curb surrounding the basket is normally closed at its top by cover 29 having an opening 30 in the path of charge material owing from the spout 11 into the basket 14. The curb connects with an enclosure, generally indicated at 31, which overlies and surrounds the opening 30 and extends from top of the curb cover to and around the loading gate in a position to enclose the path of the charge material and to unify the warm, moist atmosphere ambient to the basket with the atmosphere ambient to the loading gate.

The enclosure 31 preferably comprises two vvertical parallel side walls 32, 33 extending upwardly from top of the cover to points near top of the loading gate, front transverse wall portions indicated at 34 bridging the space between forward margins of the side walls, and a rear closure member 35 bridging the space between the bottom of the loading gate and the top of the cover 29. In order to permit occasional observation of the loading gate, transverse wall portions 34 include a segmental panel 36 which is movable to expose the loading gate.

In the illustrated form, the side walls 32, 33 present parallel free edges 37 and 38, respectively, extending along the forward outline of the enclosure from points near the top of the loading gate upwardly and forwardly and then forwardly and downwardly in a curved path to a fixed member 39 at the top of the cover 29. Member 39 forms part of transverse wall portion 34.

The segmental panel 36 comprises an upper curved segment 40 and a forward curved segment 41, the segments 40 and 41 being curved to follow the contour of the free edges 37 and 38. Upper segment 40 is hinged at its rear edge to fixed member 64 such as by hinges 65, forward segment 41 being hinged at its upper edge to the forward edge of segment 40 such as by hinges 66. The lower end of the segment 41 is connected with springs 42 which are described more fully hereinafter and ts snugly under the biasing of the springs between a vertical flange 43 of fixed member 39 and the forward edges of side walls 32, 33 when the panel is in its closed position. In this position the side margins of the panel overlie and are held firmly against the free edges 37 and 38 by the spring 42, so as to maintain a tight enclosure which will prevent leakage of cool air into, or of moist, warm air from, the enclosure. n

Movement of the panel 36 to and from open and closed positions, shown respectively in broken and solid lines in Figure l, is effected without encumbering the centrifugal assembly, by apparatus which can be manipulated by the attendant easily and quickly, which will move the panel to and from its open position in a path substantially parallel to the plane it occupies in its closed position, and which will hold the panel in either position after the attendant releases the operating handle for the apparatus.

This apparatus includes a shaft 44 having one end mounted in side wall 33 and its other end projecting through the other side wall 32 and carrying a handle 45 outside the enclosure. Adjacent the inside of each side wall, a lever 46 is fixed at one end to shaft 44 for rotationrtherewith. The other end of lever 46 is connected with the lower portion of movable panel 36 by spring 42 which can be a U-shaped leaf spring as shown in the drawings. Spring 42 is pivoted at one end, as at 47, to the free end of lever 46 and at the other end, as at 48, to an inwardly projecting arm 49 fixed to the lower portion of the panel. It will be understood that the connection between shaft 44 and the lower portion of the panel 36, through lever 46 and spring 42constitutes a toggle connection. v

In the closed position of the hood as shown by full lines in Figure l, the handle 45 is held at rest in the position shown by a projecting lug 51 thereon abutting a stop Soon the 'outside of side wall 32. In this position the pivot 47 lies to one side of the line between pivot 48 and the axis of shaft 44 so that the panel 36 is held closed by the toggle connection of the spring 42 in its compressed state and the lever 46. The enclosure is opened by rotating the handle 45 in the direction of the arrow in Figure l. As the handle is rotated, each lever 46 is simultaneously rotated counterclockwise therewith and, as the pivot 47 is movedupwardly, the lever tends to separate the arms of the spring to tension the spring so that the panel 36 is drawn upwardly with the spring 42 and lever 46 until the arm 49 butts against the shaft 44 and prevents further upward movement of this arm and the panel 36. Duringl the upward movement of the panel, the side margins of the lower portion of the panel connected with the lever 46 are held under tension by the spring 42 against the free edges 3 7 and 38. `Further rotation of the handle 45 moves the pivot 47 beyond the line between pivot 48 and the axis of shaft 44 to set up a toggle action again which holds the panel in theopen position after release of the handle 45.

To close the panel 36, the handle 45, together with lever 46, is rotated clockwise to break the toggle effect just described, whereupon the panel falls freely under its own weight or is moved positively under the influence of the rotating lever 46 and the spring 42 to its closed position. As this segment 41 approaches the end of its downward movement, each arm 49 will strike a stop 52 fixed to the inside of each side wall to cause positive movement of the segment 41 into closed position between tiange 43 and forward edges of side walls 32, 33.

It'is evident that successive loading and spinning operations can be performed without opening and closing movable lcurb top cover 29 between such operations so that the gate and the interior of the basket do not have to be exposed to the atmosphere of the room to which the centrifugal is located, and so that the warm, moist air within the basket and enclosure is not lost to this atmosphere. Furthermore, with the new top covering and enclosure, the loading gate body is positioned with its bottom spaced a short distance from the curb top, for example, only two inches, and with its gate opening 18 directly over the curb and basket openings 30 and 28, respectively, so that when the gate member 17 is raised, the charge material will flow directly from the vgate opening into the basket 14 without requiring the usual drip pan needed to guide the sugar massecuite flowing from the gate into the basket. Obviously, such apparatus eliminates the step .of scraping the Vdrip pan after the gate is closed at the completion of each loading operation. v p L A certain amount of splashing of the charge material is likely to accompany each loading operation. With the enclosure described, such splashing is conlined within the surfaces of the enclosure so that the charge material `splashed does not reach surfaces exposed to the atirnosphere outside the enclosure, which may be unsanitary and would cool the material and cause it to solidify and Stick to such exposed surfaces. Any charge'rnaterial that splashes and accumulates on surfaces of the gate and the enclosure in the present construction can be removed from these surfaces without opening the enclosure. To facilitate their removal, a spraying device is arranged within the enclosure and includes a rotatable pipe 53 within housing 39, one end 54 of the pipe being supported in and extending through one end of the housing 39 for connection with a source of washing uid, for example, superheated steam or water, and the other end of the pipe being connected with a handle 55 supported in the other end of the housing 39. A plurality ofelbow-shaped nozzles 56 are fixed to the pipe 53 for discharging the washing liuid within the enclosure. Thus, theattendant can clean the gate surface and the interior surfaces of the enclosure 31 by turning handle 55fto rotate pipe 53 and nozzles 56 to and from the positions shown in solid and broken lines in Figure 1 to direct a spray of washing uuid overvrthese surfaces;

A drip pank 57 may be positioned under` the crosshead 23 and gate member 17, asshown in full lines in Figure 1, to catch any drippings from these` parts whenever the loading gate is in closed position. The panl 57 drains over the top of the basket 14 so that the drippings do not enter the basket.

The drip pan 57 is supported at each end byv one arm 58 of a bell crank lever 59 on eachv side of the gate body 20, only one of which can be seen in the drawings. Each lever is pivoted at 60 on a lug projecting from the gate body An adjustable set screw 61 in the other arm 62 of each bell crank lever 59 extends in the path of movement of, and cooperates with, a cam 63 projecting from each end of the crosshead 23. Thus, as thev gate member 17 is' opened, cams 63 are raised with the crosshead 23 and the pan 57 falls under its own weight to swing the bell crank lever 59 counterclockwise about its pivot 60, thereby moving the pan out of the llow path of the charge material -to permit unobstructed flow of the charge material from the gate to the basket. Then, when the -gate is closed, cams 63 are lowered and act on the set screws 61` lying in the path` of movement of the cams to swing the crank arm 62 clockwise about the pivot 60 and'raise the drip pan 57 into position under the gate member 17 and the crosshead 23 to catch the drippings from these' members. On the other hand, if low grade sugars are being refined in the basket, the drip pan may be omitted.

`It will be understood that the foregoing detailed description and the accompanying drawings are intended to exemplify the invention and that the new parts, improvements and combinations herein disclosed may be embodied in various other forms and arrangements of apparatus without departing from the substance of the disclosure or the intended scope of the appended claims.

What is claimed is:

1. For a sugar centrifugal installation including a rotary basket having an open top to receive charge material, a surrounding curb, and a loading gate disposed above and toward one lside of the basket, charging apparatus comprising a top member for said curb normally closing it so as to prevent outside air currents from passing through it to the basket, said top member having an opening to lie between the basket opening and the loading gate and surrounding the flow path' of charge material passing from the gate to the basket, and an enclosure surrounding and extending between said top member opening and the loading gate and completely enclosing said ow path so as to unify the atmospheres ambient to the basket and the loading gate, said enclosure comprising two spaced side wall members at opposite sides of said loading gate extending in spaced relation from the same to parts of said top` member at opposite sides of said opening, a` backward closure member bridging the space between said side members from the bottom of the loading gate to the top member at the back of said opening, and forward closure means bridging the space between said side members and extending from an upper part of the loading gate to said top member at the front of said opening.

2. For a sugar centrifugal installation including a rotary basket having an open top to receive charge material, a surrounding curb and a loading gate disposed above and toward one side of the basket, charging apparatus comprising a top member for said curb normally closing it so as to prevent outside air currents from passing through it to the basket, said top member having an opening to lie between the basket andthe loading gate and surrounding the flow path of charge material passing from the gate to the basket, and an enclosure compris ing two spaced side wall members at opposite sides of said loading gate extending in spaced relation from the same to parts of said top member at opposite sides of said opening, a backward closure member bridging the space between said side members from the bottom ofthe loading gate to the top member at the back of said opening, and forward closure means bridging the space between said side members and extending from an upper part of the loading gate to said top member at the front of said opening so as completely to enclose said flow path, said forward closure means including a panel spaced in front of and movable to expose said gate.

3L For a sugar centrifugal installation including a rotary basket having an open top to receive charge material, a surrounding curb and a loading gate disposed above and toward one side of the basket, charging apparatus comprising a top member for said curb normally closing' it so as to prevent outside air currents from passing through it to the basket, said top member having an opening to lie between the basket and the loading gate and surrounding the flow path of charge material passing from the gate to the basltet, and an enclosure comprising two spaced side wall members at opposite sides of said loading gate extending in spaced relation from the same to parts of said top member at opposite sides of said opening and presenting parallel free edges along the forward outline of the enclosure, a backward closure member bridging the space between said side members from the bottom ot' the loading gate to the top member at the back of said opening, and forward. closure means bridging the space between said side members and extending from an upper part of the loading gate to said top member at the front of said opening so as completely to enclose said flow path, said forward closure means including a panel spaced in front of and movable to expose said gate, the panel having side margins overlying and held in close engagement with said free edges.

4. For a sugar centrifugal installation including a rotary basket having an open top to receive charge material, a surrounding curb and a loading gate disposed above and toward one side of the basket, charging apparatus comprising a top member for said curb normally closing it so as to prevent outside air currents from passing through it to the basket, said top member having an opening to lie between the basket and the loading gate and surrounding the flow path of charge material passing from the gate to the basket, and an enclosure comprising two spaced side wall members at opposite sides of said loadins7 gate extending in spaced relation from the same to parts of said top member at opposite sides of said opening and presenting parallel free edges along the forward outline of the enclosure, a backward closure member bridging the space between said side members from the loading gate to the top member at the back of said opening, forward closure means bridging the space between said side members and extending from an upper part of the loading gate to said top member at the front of said opening so as completely to enclose said flow path, said 'forward closure member including a fixed member bridging said side members at the curb top and a panel spaced in front of and movable to expose said gate, the free edges of said side wall members extending from points near the top of the loading gate upwardly :and forwardly and then forwardly and downwardly in a curved path to said fixed member, said panel being held at a fixed position relative to said side walls at its upper end and having a curvature corresponding to the contour of saidV free edges, and means for holding the lower end of the panel in closed relation to the Axed member with the panel side margins bearing firmly against these free edges.

5. For a sugar centrifugal installation including a rotary basket having an open top to receive charge material, a surounding curb and a loading gate disposed above and toward one side of the basket, charging apparatus comprising a top member for said curb normally closing` it so as to prevent outside air currents from passing through it to the basket, said top member having an opening to lie between the basket and the loading gate and surrounding the flow path of charge material passing from the gate to the basket, and an enclosure comprising two spaced side wall members at opposite sides of said loading gate extending in spaced relation from the same to parts of said top member at opposite sides of said opening and presenting parallel free edges along the forward outline of the enclosure, a backward closure member bridging the space between said side members from the loading gate to the top member at the back of said opening, and forward closure means bridging the space between said side members and extending from anupper part of the loading gate to said top member at the front of said opening so as completely to enclose said fiow path, said forward closure means including a fixed member bridging said side members at the curb top and a segmental panel spaced in front of and movable to expose said gate, the free edges of said side wall member extending from points near the top of the loading gate upwardly and forwardly and then forwardly and downwardly in a curved path to said fixed member, said panel comprising an upper segment hinged at its rear end on an axis fixed to the side members and a forward segment hinged at its upper end to the forward end of said upper segment, said segments being curved to conform with the curvature of said free edges and having side margins overlying and held in close engagement with said free edges.

6. For a sugar centrifugal installation including a rotary I basket having an open top to receive charge material, a surrounding curb and a loading gate disposed above and toward one side of the basket, charging apparatus comprising a top member for said curb normally closing it so as to prevent outside air currents from passing through it to the basket, said top member having an opening to lie between the basket and the loading gate and surrounding the ow path of charge material passing from the gate to the basket, an enclosure comprising two spaced side wall members at opposite sides of said loading gate extending in spaced relation from the same to parts of said top member at opposite sides of said opening and presenting parallel free edges along the forward outline of the enclosure, a backward closure member bridging the space between said side members from the bottom of the loading gate to the top member at the back of said opening, forward closure means bridging the space between said side members and extending from an upper part of the loading gate to said top member at the front of said opening so as completely to enclose said flow path, said forward wall portions including a fixed member bridging said side members at the curb top and a panel spaced in front of and movable to expose said gate, the free edges of the side walls extending from kpoints near the top of the loading gate upwardly and forwardly and then forwardly and downwardly in a curved path to said fixed member, said movable panel being hinged at its rear end on an axis fixed relatively to said side walls and having a curvature corresponding to the contour of said free edges, means for holding the lower end of the panel in closed relation to the fixed member with the panel side margins bearing firmly against these free edges, and manually operable means connected with the lower end of the panel and extending outside the enclosure for moving said lover end to and from an open position away from said fixed member to expose the loading gate.

7. For 'a sugar centrifugal installation including a rotary basket having an open top to `receive charge n1aterial, a surrounding curb and a loading gate disposed rabove and toward one `side of the basket, charging apparatus comprising a top member for said curb normally closing it so as to prevent outside air currents from passing through it to the basket, said top member having an opening to lie between the basket and the loading gate and surrounding the flow pathrof charge material passing from the 'gate to the'basket, and an enclosure comprising two spaced side wall members at opposite sides of said loading gate extending in spaced relation from the same to parts of said top member -at opposite sides of said opening and presenting parallel free edges along the forward outline of the enclosure, va backward closure member bridging the space between said side members from the loading gate to the top member at the back of said opening, forward closure means bridging the space between said side members Vand extending from an upper part of the loading gate to said top member at the front of said opening so as completely to enclose said flow path, said forward closure means including a fixed member bridging said side members at the curb top and a panel spaced in front of and movable to expose said gate, the free edges of the side walls extending from points near the top of the loading gate upwardly forwardly and then forwardly and downwardly in a curved path to said fixed member, 'said panel being hinged at its rear end on an axis fixed relative to said side walls and having a curvature corresponding to the contour of said free edges, means for holding the lower end of the panel in closed relation to the fixed member with the panel margins bearing firmly against the free edges, manually operable means connected with said lower end land extending outside the enclosure for moving said lower end to and from an open position away from said fixed member to expose the loading gate, and means for holding the side margins of said lower end under tension against said free edges in the opening movement of the panel.

8. For a sugar centrifugal installation including a rotary basket having an open top to receive charge material, a surrounding curb and a loading gate disposed above and toward one side of the basket, charging apparatus comprising a top member for said curb normally closing it Iso as to prevent outside air currents from passing through it to the basket, said top member having an opening to lie between the basket and the loading gate and surrounding the flow path of charge material passing from the gate to the basket, an enclosure comprising two spaced side wall members at opposite sides of 'said loading gate extending in spaced relation from the same to parts of said top member -at opposite sides of said opening and presenting parallel free edges lalong the forward outline of the enclosure, a backward closure member bridging the space between said side members from the bottom of the loading gate to the top member at the back of said opening, forward closure means bridging the space between said side members and extending from `an upper part of the loading gate to said top member at the front of said opening so as completely to enclose said flow path, said forward wall portions including Va fixed member bridging `said side members at the curb top and a panel spaced in front of and movable to expose `said gate, the free edges of the side walls extending from points near the top of the loading gate upwardly and forwardly and then forwardly 'and downwardly in a curved path to said fixed member, said movable panel being hinged at its rear end on an axis fixed relatively to said side walls and having la curvature corresponding to the contour of said free edges, means for holding the lower end of the panel in closed relation to the fixed member with the panel side margins bearingA firmly against these free edges, and manually operable means for moving the lowerend ofthe panel to and from an open position away from said fixed member to expose the loading gate, said panel holding and panel moving means comprising a rotatable -varm'having an end which describes an arc of greater diameter than the distance of the panel movement and means including a spring interconnecting said arm and the lower end of said panel. Y f

- 9. For a sugar centrifugal installation including a rotary basket having an open top to receive charge material, va surrounding curb and a loading gate ydisposed above and asaaaoe toward one side of the basket, charging apparatus comprising a top member for said curb normally closing it so as to prevent outside air currents from passing through it to the basket, said top member having an opening to lie between the basket and the loading gate and surrounding the flow path of charge material passing from the gate to the basket, an enclosure comprising two spaced side wall members at opposite sides of said loading gate extending in spaced relation from the same to parts of said top member at opposite sides of said opening and presenting parallel free edges along the forward outline of the enclosure, a backward closure member bridging the space between said side members from the bottom of the loading gate to the top member at the back of said opening, forward closure means bridging the space between said side members and extending from an upper part of the loading gate to said top member at the front of said opening so as completely to enclose said tlow path, said forward wall portions including a lixed member bridging said side members at the curb top and a panel spaced in front or and movable to expose said gate, the free edges of the side walls extending from points near the top of the loading gate upwardly and forwardly and then forwardly and downwardly in a curved path to said xed member, said movable panel being hinged at its rear end on an axis fixed relatively to said side walls and having a curvature corresponding to the contour of said free edges, means for holding the lower end of the panel in closed relation to the iixed member with the panel side margins bearing firmly against these free edges, and manually operable means for moving the lower end of the panel to and from an open position away from said fixed member to expose the loading gate, said panel holding and panel moving means comprising a rotatable arm having an end which describes an arc of greater diameter than the distance of the panel movement and means including a leaf spring pivoted at its upper end to said arm and at its lower end to a part on the lower end of the panel.

10. For a sugar centrifugal installation including a rotary basket having an open top to receive charge material, a surrounding curb and a loading gate disposed above and toward one side of the basket, charging apparatus comprising a top member for said curb normally closing it so as to prevent outside air currents from passing through it to the basket, said top member having an opening to lie between the basket and the loading gate and surrounding the ow path of charge material passing from the gate to the basket, an enclosure comprising two spaced side wall members at opposite sides of said loading gate extending in spaced relation from the same to parts ot said top member at opposite sides ot' said opening and presenting parallel free edges along the forward outline off the enclosure, a backward closure member bridging the space between said side members from the bottom of the loading gate to the top member at the back of said opening, forward closure means bridging the space between said side members and extending from an upper part or" the loading gate to said top member at the front of said opening so as completely to enclose said flow path, said forward wall portions including a xed member bridging said side members at the curb top and a panel spaced in front of and movable to expose said gate, the free edges of the side walls extending from points near the top of the loading gate upwardly and forwardly and then forwardly and downwardly in a curved path to said lixed member, said movable panel being hinged at its rear end on an axis fixed relatively to said side walls and having a curvature corresponding to the contour of said free edges, means for holding the lower end of the panel in closed relation to the fixed member with the panel side margins bearing rmly against these free: edges, and manually operable means for moving the lower end of the panel to and from an open position away from said fixed member to expose the loading gate, said panel holding and panel moving means comprising .a rotatable arm having an end which describes an are of greater diameter than the distance of the panel movement and means including a leaf spring pivoted at its upper end to said arm and at its lower end to a part on the lower end of the panel, the ends of said arc lying to one side of a line between the pivotal axis of said arm and the pivotal axis of the lower end of said spring in the opened and closed positions of the panel so as to hold the panel in these positions.

References Cited in the le of this patent UNITED STATES PATENTS 1,123,210 Shepherd Dec. 29, 1914 1,540,645 Meikle June 2, 1925 2,328,394 Neuman Aug. 31, 1943 2,337,817 Hertrich Dec. 28, 1943 

